freebsd-dev/contrib/apr/network_io/unix/socket_util.c
2014-05-27 07:15:14 +00:00

76 lines
2.5 KiB
C

/* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "apr_network_io.h"
#include "apr_poll.h"
APR_DECLARE(apr_status_t) apr_socket_atreadeof(apr_socket_t *sock, int *atreadeof)
{
apr_pollfd_t pfds[1];
apr_status_t rv;
apr_int32_t nfds;
/* The purpose here is to return APR_SUCCESS only in cases in
* which it can be unambiguously determined whether or not the
* socket will return EOF on next read. In case of an unexpected
* error, return that. */
pfds[0].reqevents = APR_POLLIN;
pfds[0].desc_type = APR_POLL_SOCKET;
pfds[0].desc.s = sock;
do {
rv = apr_poll(&pfds[0], 1, &nfds, 0);
} while (APR_STATUS_IS_EINTR(rv));
if (APR_STATUS_IS_TIMEUP(rv)) {
/* Read buffer empty -> subsequent reads would block, so,
* definitely not at EOF. */
*atreadeof = 0;
return APR_SUCCESS;
}
else if (rv) {
/* Some other error -> unexpected error. */
return rv;
}
/* Many platforms return only APR_POLLIN; OS X returns APR_POLLHUP|APR_POLLIN */
else if (nfds == 1 && (pfds[0].rtnevents & APR_POLLIN) == APR_POLLIN) {
apr_sockaddr_t unused;
apr_size_t len = 1;
char buf;
/* The socket is readable - peek to see whether it returns EOF
* without consuming bytes from the socket buffer. */
rv = apr_socket_recvfrom(&unused, sock, MSG_PEEK, &buf, &len);
if (rv == APR_EOF) {
*atreadeof = 1;
return APR_SUCCESS;
}
else if (rv) {
/* Read error -> unexpected error. */
return rv;
}
else {
*atreadeof = 0;
return APR_SUCCESS;
}
}
/* Should not fall through here. */
return APR_EGENERAL;
}